Researchers Record Live Neurons Firing Inside a Rodent’s Brain

In Brief

A new "light sculpting" technique allowed researchers to see an area roughly one-eighth of a cubic millimeter in size in a mouse's brain light up in real time while it worked.

This technique could one day allow us to see human brains at work, which could lead to treatment innovations for neurological disorders or perhaps even cures.

Brains On Display

For thousands of years, humans have been trying to understand just how our brains work, and technological advances in recent decades have brought with them a wealth of information. However, for all that innovation, we’ve still yet to actually see one actively working. Though scientists have been trying for years, we’ve yet to see the neurons in a human brain all fired up in real time, but now we are on the verge of just that.

Researchers have already been able to see live electrical activity inside a 302-neuron roundworm brain and larval zebrafish brains, which house 100,000 neurons. Now, a team of researchers at the Rockefeller University led by Dr. Alipasha Vaziri have developed a “light sculpting” technique that has allowed them to successfully see part of a mouse’s brain lighting up in real time while the animal does physical work.

Unlike the brains of a roundworm or larval zebrafish, a rat’s brain is opaque and with millions of neurons, which is why this special imaging technique had to be formulated. The researchers first genetically altered the mice so that their neurons would emit light when signaling to one another. They then dispersed short pulses of laser light into their colored components and then reassembled them into a “sculpted” excitation sphere. They could then scan that sphere to illuminate the neurons within it before moving on to the next plane of neurons.

Using this method, the team was able to capture fluorescent neurons firing in a test rodent’s brain while its legs were running on a customized treadmill and its head was immobilized. All the activity they recorded took place in an area roughly one-eighth of a cubic millimeter in size within the mouse’s cortical column, the part of the brain that plans movement.

Credit: Rockefeller University

Understanding the Brain

“The ultimate goal of our work is to investigate how large numbers of interconnected neurons throughout the brain interact in real time and how their dynamics lead to behavior,” says lead author Alipasha Vaziri in a statement. So why all the fuss over seeing live firing neurons? Because we can learn a lot about the brain from that information.

By mapping out the brains of individuals suffering from specific diseases, we can learn which areas of the brain are impaired as a result of the disease. Scientists could also focus on the areas of the brain that are responsible for certain actions as those actions occur and then use that information to develop cures or treatments for problems impeding those actions.

Maps of the brains of exceptionally gifted people could tell us which areas are most active during certain processes as well. This could lead to innovations that help us all tap into the true potential of our own brains.